The invention relates to an apparatus for fire-fighting comprising a fire-extinguishing nozzle connected to an extinguisher fluid supply via a pipe and comprising an alarm device which delivers a warning signal at the beginning of a fire-extinguishing process. Such apparatus is installed, for example, in fixed positions in buildings or other equipment to be protected from fire. As a rule, there are provided devices which automatically trigger the outflow of extinguisher fluid when a fire occurs.
In many cases, the alarm devices deliver a warning in the form of an acoustic signal perceptible over a fairly large distance when the fire-extinguishing process begins. In this way, it is ensured that also the fire-extinguishing process which begins in an unobserved area and consequently the fire itself is noticed by persons in the vicinity of the affected area.
For this purpose known sprinkler installations are provided with so-called “sprinkler bells”, which are driven in the fashion of a turbine by the water flowing through the pipe in the event of a fire. In fire-fighting apparatus in which gaseous media are used as extinguisher fluid, it is also known that some of the gas is passed through a pneumatically operating siren.
The disadvantage of known alarm systems with sprinkler systems in which the alarm device is driven hydraulically by the liquid extinguisher medium is that a drive shaft leading out of the respective pipe must be present. Leaks may occur in the area of this rotary transmission. In addition, the drive mechanism impedes the flow of extinguisher fluid in the pipe. In fire-extinguishing apparatus in which some of the gaseous extinguisher fluid is branched off to drive the alarm device, leaks may also occur. The risk of leaks occurring is particularly high in systems operating at high pressures. Such high pressures are required especially when a liquid extinguisher fluid or a mixture of liquid and gaseous extinguisher media is atomised by the fire-extinguishing nozzles to form a fire-extinguishing mist. With such fire-extinguishing mists a fire can be fought particularly effectively with a low consumption of fire-extinguishing agents.